Using flash in Av mode

OK, so don't tar and feather me for asking a stupid question! Can you use the flash in ETTL mode when shooting in the AV mode or is the flash normally best used in Manual mode? Does the flash actually do anything in Av mode?

I've also noticed that when shooting outdoors, with my flash in ETTL mode and the camera in AV mode that I have to have the "high-sync" feature on or the pictures are totally blown out and white? Why is this?

Do I keep the high-sync feature on when using the flash in ETTL and the camera in manual or is there no need for it?

lilpacheco wrote in post #5516437
OK, so don't tar and feather me for asking a stupid question! Can you use the flash in ETTL mode when shooting in the AV mode or is the flash normally best used in Manual mode? Does the flash actually do anything in Av mode?

I've also noticed that when shooting outdoors, with my flash in ETTL mode and the camera in AV mode that I have to have the "high-sync" feature on or the pictures are totally blown out and white? Why is this?

Do I keep the high-sync feature on when using the flash in ETTL and the camera in manual or is there no need for it?

The flash works in ETTL mode regardless of what the camera mode is set to! The determination of camera mode is solely based upon what YOU want your camera to behave like. Av would be perfectly fine if you were using flash in sunlight, as a backlight fill or to reduce racoon eye shadow. But Av sucks big time if you use it in a dimly lit room, because under Av the stupid camera will try to set itself for the low ambient light (even though it has flash!) and that results in absurdly long shutter speeds that cannot possibly be hand held!

And that brings us back to why most pros set the camera in M, rather than let the camera's Av stupidity prevail.

Using ETTL with Av mode will cause the camera to use the flash for fill. This may or may not be what you want.

What ISO are you shooting outdoors? In Av mode with flash the fastest shutter speed is 1/200 (without HSS), so your lens may not be able to close down enough to properly expose the image.

Wilt wrote in post #5516471
The flash works in ETTL mode regardless of what the camera mode is set to! The determination of camera mode is solely based upon what YOU want your camera to behave like. Av would be perfectly fine if you were using flash in sunlight, as a backlight fill or to reduce racoon eye shadow. But Av sucks big time if you use it in a dimly lit room, because under Av the stupid camera will try to set itself for the low ambient light (even though it has flash!) and that results in absurdly long shutter speeds that cannot possibly be hand held!

And that brings us back to why most pros set the camera in M, rather than let the camera's Av stupidity prevail.

OK, this makes total sense and explains so many of my indoor shots! Time to practice, practice! What a relief I figured this out!

Wilt wrote in post #5516471
The flash works in ETTL mode regardless of what the camera mode is set to! The determination of camera mode is solely based upon what YOU want your camera to behave like. Av would be perfectly fine if you were using flash in sunlight, as a backlight fill or to reduce racoon eye shadow. But Av sucks big time if you use it in a dimly lit room, because under Av the stupid camera will try to set itself for the low ambient light (even though it has flash!) and that results in absurdly long shutter speeds that cannot possibly be hand held!

And that brings us back to why most pros set the camera in M, rather than let the camera's Av stupidity prevail.

And this, my friend, is what confused the heck out of me for the longest time! Av is my favorite mode *but* not with flash it ain't anymore!

Since a flash will freeze motion, you're better off in Tv mode (or M mode). Hell, even greenbox mode will beat the pants off of Av mode with flash!

Gatorboy wrote in post #5516493
Using ETTL with Av mode will cause the camera to use the flash for fill. This may or may not be what you want.

What ISO are you shooting outdoors? In Av mode with flash the fastest shutter speed is 1/200 (without HSS), so your lens may not be able to close down enough to properly expose the image.

The particular time I'm thinking of I had my ISO at 100 I believe. Does it hurt to always have HSS on?

lilpacheco wrote in post #5516560
Does it hurt to always have HSS on?

Well, in HSS mode the light output intensity drops off dramatically, limiting the max distance that you can take a flash photo. If if HSS is off, the high shutter speed results in dark band across part of the photo...which makes me wonder why the Canon engineers did not simply leave HSS always enabled?!